A conventional franking meter includes a backed-up non-volatile memory for storing total consumption, i.e. the cumulative value of all franking operations performed since the meter was put into operation. In order to be able to bill monthly consumption, and to be able to perform certain checks sporadically, the postal authorities in charge of the meter require the user to hand-fill a monthly form having one line per day. At the end of the day, the user reads the total consumption as displayed on a display of the meter, writes it down on the form, then calculates the day's consumption by subtracting the total consumption recorded on the previous day from the presently-displayed total, and writes down the day's consumption on the form as well.
Such forms present numerous difficulties:
Users are not always careful in calculating and writing down daily consumption figures, and even careful users can make mistakes.
A dishonest user may be tempted to fake the amounts declared. Provision is made for sporadic checks, but they are difficult to implement since they require an agent of the postal authority to pay a visit and read the real total consumption figure on the meter.